text: N-acetylneuraminic acid (Neu5Ac) is one of the two most common sialic acid in mammals. It is a monosaccharide with a backbone of 9 carbons. It is usually attached to glycoproteins or gangliosides on a terminal end via α(2,3), α(2,6), and α(2,8) linkage.
  Neuraminidase is an enzyme which hydrolyses that bond to produce a free neuraminic acid and a glycoprotein or a sugar chain. Influenza virus will bind via the hemagglutinin protein on these sialic acid attached glycoproteins on the cell membrane.